1. Field of the Invention
This invention pertains to a solid cleansing composition, of the general type and shape of a cleansing bar. A solid cleansing bar is provided with high filler loading, and simultaneously excellent lathering, texture, feel characteristics and aesthetics. The bar can be produced by conventional plodding technology, and yet exhibits superior properties when compared with related technology prepared according to tableting processes which are not nearly as productive.
2. Background of the Prior Art
U.S. patent application Ser. No. 08/621,965, filed Mar. 26, 1996, now U.S. Pat. No. 5,756,438, the entirety of which is incorporated herein by reference, discloses cleansing bars containing a high proportion of fillers, in particular fillers such as maltodextrin or dextrose. Other fillers, including other carbohydrates, starches and dextrins, as well as inorganic particulate fillers such as talc, kaolin, bentonite clay, carbonate or sulphate salts, sugars and crystalline polyols are noted. The filler is combined with a surfactant system which includes anionic surfactants, and/or non-ionic surfactants, which may be used together with zwitterionic and cationic surfactants. While this patent application describes the potential use of quaternary ammonium chlorides, use of the same is not exemplified. One problem with using such quaternary surfactants is the pH level generally encountered in solid cleansing products, even non-soap cleansing products of the type addressed herein and in the referenced pending application. Specifically, a neutral-alkaline pH may generate, through decomposition, free amines, and the associated unpleasant odor as well as product discoloration. Additionally, many commercially available quaternary surfactant compositions comprise residual free amines.
U.S. Pat. No. 5,756,438 describes a process for production that involves melting a waxy binder, mixing it with the remaining components and subsequently tableting the so processed mass. While the processing specified gives rise to a highly desirable product, it is specifically disclosed that the high production techniques generally used in bar products, referred to as "plodding", cannot be used. This necessarily imparts significant costs to the process of manufacture.
Other highly filled bar products have been attempted, but are generally inadequate in one or more important product considerations. These include lathering, or foaming. In general, the presence of a high degree of filler complicates the ability to produce adequate foaming. Another essential aspect of the product is its feel or texture. The higher proportion of filler typically gives rise to a "dragging" or "rough" feeling in the bar itself. Similarly, the product must be aesthetically pleasing. Commercial products with a high filler loading provide an unattractive bar, that cracks or splinters quickly upon use, and/or presents a grainy, pebbled surface.
Japanese Kokai 56-84798, published Jul. 10, 1981, is directed to a soap composition which contains, by weight, 60-90% starch or cellulose. Unlike the non-soap product of U.S. Pat. No. 5,756,438, and the claimed invention, the Kokai is directed to a granular soap which is a compacted powder intended to achieve rapid disintegration, and through disintegration, washing. The product is intended for use as a tablet which disintegrates upon admixture with water. Thus, while other high-filler compositions are known, none provide a suitable combination of acceptable lathering performance, acceptable filler texture, aesthetic properties and ease of manufacturing. The provision of a personal, non-soap cleansing bar, meeting these goals, continues to be an object of those of skill in the art.